I'm a developer who occasionally needs to do server stuff just to get the environment he needs for working.
I have an AD domain (all servers are 2008 R2) with, presumably, a default forest. Works fine. Built a second domain elsewhere, in which I created a SharePoint farm. Now I want to move that domain (which uses a Server Core DC) into the existing forest.
Lots of instructions (and notes about child domains and tree domains), but I'm getting the feeling that all those instructions presume that the new domain is being created within that existing forest. In my case, I want to move the new domain into the old forest (to preserve the various user and service accounts).
What are my options?
[added after a couple responses]
Looking at the first two responses, let me add a wee bit about why I even consider doing this.
I built the SharePoint domain (using virtualized Server Core for the domain controller and one virtual machine for SharePoint, which then uses the Sql Server of the host server for its data store (and I wanted to have a Kerberos environment)) "away" from my "production" environment but using the same ISP. So, all machines are running IPs within the same 256-group. Performance was just fine.
I then built a Windows 7 machine just to connect with that new domain and on which to do whatever development doesn't need to be done directly on the SharePoint server. Works fine.
But upon then connecting with the server machines in the new domain via Remote Desktop Connections, I found that any action taken on the remote server required about 5 seconds to be seen from the Win7 machine. Completely unacceptable for the purpose intended.
Went back to my existing equipment to check its performance, and connecting to those servers via a different Win7 machine show the usual instantaneous response.
So, I concluded (without any real evidence) that the new domain was conflicting with the old domain (even though the old domain isn't affected at all).
I'm now getting the feeling that I can leave the two domains separate (there is certainly no need for them to communicate). But what could be causing the unacceptable performance of Remote Desktop between the Win7 and server machines?
I think it runs down into reinstall. I do not think forests can be merged, which is what you ask for.
It is possible to merge elements of one domain into another. MS supply migration tools - but its definitely not for the faint of heart and you would need a very good understanding of the mechanism and working of AD.
Migrating a domain into another is days or weeks of work and would leave you with loads of security related issues in sharepoint if it worked at all after migrating... better forget the idea.
You can backup and restore a sharepoint installation in minutes - assuming you have a web server and sql server ready and waiting. This I have done on numerous occasions and it just works.
I don't think this has anything to do with multi domain, permissions or anything else. I would verify the remote desktop settings are right, that the network connectivity is solid and the Win7 box has a healthy network connection. Maybe try another remote access tool (like VNC) to prove that the domain is not involved.
\\Greg